A device for ejecting droplets of a fluid, for example an ink jet printer, is well known in the art, see for an overview for example Stephen F. Pond, Inkjet Technology and Development Strategies, Torrey Pines Research, 2000. In such a device, droplets are ejected through an orifice by applying a force on a fluid. The device comprises at least one orifice provided with an electromechanical transducer. The best known examples of electromechanical transducers are thermal transducers and piezoelectric transducers. In the piezoelectric ink jet technique, a piezoelectric element deforms under the influence of an electric pulse. The bending deformation of the piezoelectric element generates a pressure in a fluid chamber, which may eventually lead to the ejection of a droplet of a fluid through the orifice. In thermal ink jet, the fluid is locally heated, such that the fluid is locally converted into a vapor. This evaporation of a part of the fluid generates a force, which may eventually lead to the ejection of a droplet of a fluid through the orifice.
However, both techniques are not suited for operation at high temperature. Thermal ink jet is only suited for ejecting fluids, having a relatively low boiling point, because this technique requires the evaporation of a part of the fluid to generate a force in the fluid. Piezoelectric elements cannot operate at very high temperatures and are therefore not suited for ejecting droplets of a fluid at high temperature.
WO 2010063576 describes a device for jetting droplets of a fluid at a high temperature, wherein the fluid is actuated by generating a Lorentz force in the fluid. The device is suited to eject droplets of fluid at a high temperature. A Lorentz force is generated in the fluid, by applying an electrical pulse to the fluid, the fluid being positioned in a magnetic field. A Lorentz force can only be generated if the fluid is an electrically-conductive fluid. In WO 2010063576, a device for jetting droplets of an electrically-conductive fluid, is disclosed. However, the device disclosed in WO 2010063576 is not suited to jet droplets of an electrically non-conductive fluid. In this device, the actuation means, provided for actuating the electrically conductive fluid is positioned in close proximity to the orifice. As a consequence, droplets of an electrically non-conductive fluid cannot be jetted by the device according to WO 2010063576.
It is an object of the invention to provide a device for ejecting droplets of an electrically non-conductive medium having a high melting point at high temperature.